1. Field of the Invention
The present invention relates generally to systems and methods for automated analysis and imaging of tissue engineered constructs, such as genetic material, bioartificial tissue; bioartificial tendons and the like, and in particular to a system and computer-implemented method for imaging and analyzing tissue constructs in a controlled environment in the field of tissue engineering and cell biology.
2. Description of Related Art
In the field of tissue engineering, bioartificial tissue (BAT) cellular constructs, such as bioartificial tendons, are analyzed for various parameters, such as response to loading, response to foreign substances, compaction of matrix and alteration of properties, etc. For example, when analyzing bioartificial tendons, partial samples of human supraspinatus tendons are harvested from debrided tissue of patients undergoing open or arthroscopic surgical repair of injured tendons. These harvested samples, and in particular the supraspinatus tendon cells, are isolated from the specimens, minced into small pieces and rinsed with a nutrient to remove red blood cells.
Next, these minced tendons are digested with a collagenase in a specified medium, together with antibiotics and buffering agents. Cells that are cultured in three-dimensional collagen gels express a more native state phenotype, since these cells form a syncytial network that is capable of being mechanically loaded. In addition, these types of cells remodel their matrix by eliminating water, reorganizing and aligning the collagen fibrils. Still further, the ability of these cells to withstand mechanical loading in a native matrix provides additional research data. Specifically, in tissues, these cells are capable of bearing strains and altering the expression profile consistent with immobilization, moderate activity or repetitive loading.
In order to create bioartificial tissue or BAT units, the cell-matrix mixture is dispensed into a trough of defined geometry, in a membrane in a culture plate or culture well by drawing the flexible membrane into a trough in a Delrin disc with vacuum holes placed in the disc. After vacuum is applied to the flexible well bottom, the membrane is drawn downward into the cavity of the disc. Flexible but inelastic nylon mesh anchors are bonded to the membrane at predetermined poles, and anchor stems at each end of the nylon mesh anchors connect to a cell-gel material that is transferred into each well. The anchor stems allow the bonding thereto of the collagen gel and cell mixture. The vacuum is released after gelation and the cell-gel construct returns to the horizontal plane of the flexible membrane.
When it is desired to mechanically load these BATs, such mechanical loading may be achieved by placing an arctangle loading post beneath each well, for example, in a six-well culture plate, and using a vacuum to displace the flexible membrane downward. This results in a uniaxial strain on the BAT. Accordingly, cells may be cultured in a mechanically active and three-dimensional culture environment, which is particularly useful in the field of tissue engineering.
In analyzing these three-dimensional cell-matrix constructs, it is beneficial to conduct this analysis over time in a study. Typically, the cells within these constructs will begin to form attachments immediately, i.e., on the day of plating, and will subsequently reorganize and contract the matrix within a few hours to days. Accordingly, measurements of the matrix contraction under the influence of various physical and biochemical factors indicate the impact of each factor on the cellular function.
According to the prior art and with respect to tissue, engineered constructs, and genetic material generally, measurements of matrix compaction, organization, contraction and other parameters are performed manually by periodically removing the culture plates from the controlled environment, e.g., inside an incubator apparatus, to access an external imaging device, such as a camera or a scanner. Depending upon the effect of being measured, this process may need to be repeated every few hours, day and night, for several days. Not only is such a process labor intensive, it also leads to damaging influences for the cell cultures themselves. Accordingly, it is preferable to analyze and monitor these constructs, without repeatedly exposing these constructs to dramatic environmental changes.